全文获取类型
收费全文 | 308篇 |
免费 | 37篇 |
国内免费 | 7篇 |
专业分类
化学 | 9篇 |
晶体学 | 1篇 |
力学 | 132篇 |
数学 | 168篇 |
物理学 | 42篇 |
出版年
2023年 | 4篇 |
2022年 | 8篇 |
2021年 | 3篇 |
2020年 | 13篇 |
2019年 | 8篇 |
2018年 | 11篇 |
2017年 | 20篇 |
2016年 | 10篇 |
2015年 | 13篇 |
2014年 | 18篇 |
2013年 | 30篇 |
2012年 | 11篇 |
2011年 | 17篇 |
2010年 | 24篇 |
2009年 | 17篇 |
2008年 | 16篇 |
2007年 | 13篇 |
2006年 | 18篇 |
2005年 | 11篇 |
2004年 | 6篇 |
2003年 | 10篇 |
2002年 | 11篇 |
2001年 | 12篇 |
2000年 | 8篇 |
1999年 | 13篇 |
1998年 | 8篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有352条查询结果,搜索用时 359 毫秒
61.
62.
Hoda Bidkhori 《Journal of Combinatorial Theory, Series A》2012,119(3):765-787
In this paper we study finite Eulerian posets which are binomial, Sheffer or triangular. These important classes of posets are related to the theory of generating functions and to geometry. The results of this paper are organized as follows:
- •
- We completely determine the structure of Eulerian binomial posets and, as a conclusion, we are able to classify factorial functions of Eulerian binomial posets.
- •
- We give an almost complete classification of factorial functions of Eulerian Sheffer posets by dividing the original question into several cases.
- •
- In most cases above, we completely determine the structure of Eulerian Sheffer posets, a result stronger than just classifying factorial functions of these Eulerian Sheffer posets.
63.
In the present paper, some new basis-free expressions for an arbitrary objective corotational rate of the general Eulerian
strain measures are provided which are in compact form. Moreover, a complete discussion on the requirements for the continuity
of the objective corotational rates are presented.
相似文献
64.
In this paper an Eulerian rate-dependent single crystal model that accounts for high-strain rates, large strains and rotations is developed. The viscoplastic law as well as the evolution equations for the lattice are written in terms of vectorial and tensorial quantities associated with the current configuration. The viscoplastic law is obtained from Schmid law using an overstress approach. Such an expression for the viscoplastic law is motivated by the microdynamics of crystal defects. A general analysis of the plane-strain response of the proposed rigid-viscoplastic single crystal model is presented. It is shown that only one differential equation, involving the orientation of one composite in-plane slip system, is necessary to describe the lattice evolution. Several two-dimensional boundary value problems, such as equal-channel die extrusion and channel die compression are selected to illustrate the predictive capabilities of the model. The results show that even at relatively low strain rates the viscosity plays an important role in the development of localized deformation modes. At high crosshead velocity, the plastic properties and crystal anisotropy are less important while inertia effects are dominant. Finally, the grains interaction is investigated by analyzing the compression of a grains multicrystal. 相似文献
65.
In this paper we shall first introduce the Pascal k-eliminated functional matrices Pn,k[xyz] and CPn,k[xyz]. Then, using these matrices we obtain several important combinatorial identities. Finally, using the matrix inversion of Pn,k[xyz] and CPn,k[xyz], we derive an interesting formula for Eulerian numbers [7] 相似文献
66.
A further study on the postbuckling of extensible elastic rods 总被引:1,自引:0,他引:1
67.
We define a noncommutative algebra of flag-enumeration functionals on graded posets and show it to be isomorphic to the free associative algebra on countably many generators. Restricted to Eulerian posets, this ring has a particularly appealing presentation with kernel generated by Euler relations. A consequence is that even on Eulerian posets, the algebra is free, with generators corresponding to odd jumps in flags. In this context, the coefficients of the cd-index provide a graded basis. 相似文献
68.
J.M. Senoner M. Sanjos T. Lederlin F. Jaegle M. García E. Riber B. Cuenot L. Gicquel H. Pitsch T. Poinsot 《Comptes Rendus Mecanique》2009,337(6-7):458-468
Large-Eddy Simulations (LES) of an evaporating two-phase flow in an experimental burner are performed using two different solvers, CDP from CTR-Stanford and AVBP from CERFACS, on the same grid and for the same operating conditions. Results are evaluated by comparison with experimental data. The CDP code uses a Lagrangian particle tracking method (EL) while the code AVBP can be coupled either with a mesoscopic Eulerian approach (EE) or with a Lagrangian method (EL). After a validation of the purely gaseous flow in the burner, liquid-phase dynamics, droplet dispersion and fuel evaporation are qualitatively and quantitatively evaluated for three two-phase flow simulations. They are respectively referred as: CDP-EL, AVBP-EE and AVBP-EL. The results of the three simulations show reasonable agreement with experiments for the two-phase flow case. To cite this article: J.M. Senoner et al., C. R. Mecanique 337 (2009). 相似文献
69.
The paper presents a semi‐implicit algorithm for solving an unsteady fluid–structure interaction problem. The algorithm for solving numerically the fluid–structure interaction problems was obtained by combining the backward Euler scheme with a semi‐implicit treatment of the convection term for the Navier–Stokes equations and an implicit centered scheme for the structure equations. The structure is governed either by the linear elasticity or by the non‐linear St Venant–Kirchhoff elasticity models. At each time step, the position of the interface is predicted in an explicit way. Then, an optimization problem must be solved, such that the continuity of the velocity as well as the continuity of the stress hold at the interface. During the Broyden, Fletcher, Goldforb, Shano (BFGS) iterations for solving the optimization problem, the fluid mesh does not move, which reduces the computational effort. The term ‘semi‐implicit’ used for the fully algorithm means that the interface position is computed explicitly, while the displacement of the structure, velocity and the pressure of the fluid are computed implicitly. Numerical results are presented. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
70.